Method for controlling the power consumption of a hydrodynamic clutch by controlling the volumetric efficiency and a hydrodynamic clutch

ABSTRACT

A method for controlling the power consumption of a starting element ( 1 ) in the form of a hydrodynamic clutch ( 2 ). The clutch comprises an impeller ( 4 ) and a turbine wheel ( 5 ), which together form at least one toroidal working chamber ( 6 ) that can be filled with an operating medium, and is located in a drive train ( 3 ) with at least one other drive motor that can be coupled to the hydrodynamic clutch. The method is characterized in that the power consumption can be freely adjusted as a function of the volumetric efficiency of the hydrodynamic clutch and the method has the following characteristics: the supply or evacuation of the operating medium to or from the working chamber is influenced by the generation and introduction of a static superposition pressure in the closed rotating circuit; the operating medium is supplied or evacuated to or from the working chamber by the application of a superposition or influencing pressure to the operating medium level in the operating medium reservoir ( 40 ).

BACKGROUND OF THE INVENTION

The invention relates to a method for controlling the power consumptionof a hydrodynamic clutch, in particular as starting element in a drivetrain by controlling the volumetric efficiency.

During the starting process, i.e. the run-up of the drive motor andsimultaneous transmission of torque on the output unit in a drive train,in particular in vehicles but also in stationary units, the problem ofenergy consumption of the drive motor is increasingly the center ofattention since during this process usually too little energy forself-acceleration of the drive motor is available. As starting elementsin vehicles hydrodynamic clutches are used for this purpose among otherthings. They are well-known in a multiplicity of designs. Reference ismade to the publication Voith:“Hydrodynamics in motive powerengineering”, Vereinigte Fachverlage, Krauskopf Engineer Digest, Mainz1987. The starting elements are usually integrated in a gear box unit.The gear box unit has for this a first hydrodynamic transmission partand a further second transmission part, which is usually preferablyformed by a mechanical transmission part for application in vehicles.Since the power consumption of the hydrodynamic clutch is dependent onits design and not on a machine, which is at least indirectly connectedto the hydrodynamic clutch on the output side, during the installationof such a component between a drive motor and a machine it is to beconsidered that for each load condition between the machine and thehydrodynamic clutch also a state of equilibrium must be ensured betweenthe drive motor and the hydrodynamic component. Thereby the powerreleased by the drive motor is in the rarest case completely availableto the gear unit, in particular the hydrodynamic component, during thestarting process. Power for auxiliary machines, like for example fans,generators, pumps and so on, which are positioned before the startingelement respectively the gear inlet, must thereby be subtracted from theavailable drive power. For the use of a hydrodynamic component in formof a hydrodynamic clutch the following specified benefits of thehydrodynamic power transmission are thereby desirable for the startingprocess: wear-free as well as vibration reducing and thermally stable.In connection with drive motors for different application functionsconcrete demands are made regarding the transfer characteristic alsoduring the starting process. In particular for the application invehicles a certain behavior during the starting process, in particular acertain power consumption by the impeller of the hydrodynamic clutch, isdesired in order to be able to drive the drive motor in an optimizedoperating range regarding a certain parameter. During the startingprocess at low speeds it is therefore required that a suitable surplusmoment is present for the self-acceleration of the drive motor in orderto realize a motor start-up that is relieved as much as possible.

SUMMARY OF THE INVENTION

It is therefore the task of the invention, to further develop a startingunit of the kind initially specified, in particular a method forcontrolling the power consumption, in such a manner that said startingunits are suitable in particular for the application in drive trains ofvehicles or other ranges of application, whereby besides the advantagesof the hydrodynamic power transmission also a substantially relievedstart-up of the drive motor should be ensured. The design of thestarting unit should be characterized by a low expenditure for design,production and control and it should be economical. Furthermore thesolution according to the invention, independently of the field ofapplication at the hydrodynamic component, is to require only slightmodifications.

According to the invention the power consumption as a function of itsvolumetric efficiency is freely adjustable with a method for controllingthe power consumption of a starting element in form of a hydrodynamicclutch, comprising an impeller and a turbine wheel, which form with oneanother at least one toroidal working chamber that can be filled withoperating medium, in a drive train with at least another drive motorthat can be coupled with the hydrodynamic clutch. This possibility offree adjusting makes it possible, regarding different criteria, forexample energy consumption and pollutant emission, to try to achieveoptimized operating points in the characteristic diagram of the drivemotor.

Thereby a change of the power to be received takes place by controllingthe volumetric efficiency of the hydrodynamic clutch when a value ispresent, which characterizes the power desired to be received of thehydrodynamic clutch at least indirectly. The controlling of thevolumetric efficiency takes thereby place preferably via creating and/orapplying of an influence pressure on a resting medium, in particular onan operating medium level which arises in an operating medium reservoirwithin the scope of an operating medium utility system or on a controlmedium level. Thereby a portion of the operating medium in the workingchamber is directed during the operation of the hydrodynamic clutch in aclosed circuit between at least one outlet from the toroidal workingchamber between impeller and turbine wheel and at least one inlet intothe toroidal working chamber, whereby the inlet is connected with anoperating medium reservoir which is pressure tight closed in relation toits surrounding. A manipulated variable is then created for thegeneration of an influence pressure on the medium resting in theoperating medium reservoir and the servo unit is triggered. Filling oremptying takes place up to the point of reaching a pressure balancebetween the operating medium level in the operating medium reservoir andthe rotary closed circuit.

A hydrodynamic clutch according to one form of the invention comprisesat least two rotating circuit parts in the form of two impellers, whichform with one another at least one toroidal working chamber, which canbe filled with operating medium and in which a rotary working circuitarises during operation of the hydrodynamic clutch. An inlet and anoutlet are assigned to the toroidal working chamber, which is connectedwith a closed circuit. Said working chamber comprises the workingcircuit and an external element, i.e. an element directed outside of thetoroidal working chamber, which is connected with the working circuit.The external element of the circuit serves thereby among other thingsthe purpose of directing the operating medium for the purpose ofcooling. This closed circuit is designed according to the inventionpressure tight. This means that the inlet, in particular the inlet areato the working chamber, and the outlet, in particular the outlet areaare designed fluid tight in relation to the hydrodynamic clutch and thatfurther the operating medium guide distance between the inlet and theoutlet is completely sealed in the external element of the closedcircuit, i.e. outside of the toroidal working chamber.

The solution according to the invention makes it possible that duringoperation of the hydrodynamic clutch operating medium is directed in theexternal element of the circuit with removal of operating medium fromthe working circuit into the external element of the closed circuit and,since the whole circuit is designed as a closed circuit, operatingmedium is again supplied to the inlet. Due to the pressure tight designa pressure in the closed system, created by the hydrodynamic clutch, ismaintained during the operation of the hydrodynamic clutch, i.e. duringrotation of an impeller and therefore by slaving at least anotherimpeller by means of the working circuit. This circuit can be designatedthereby by itself as cooling circuit, as heat can be dissipated byradiant heat over the line connections between the outlet and the inlet.Therefore already this design makes a cooling circuit possible.

If under a further aspect means for the generation of an influencepressure on the operating medium directed in the closed circuit areplanned, the possibility consists to control additionally the volumetricefficiency of the hydrodynamic clutch.

Under a further aspect at least one junction location for the optionalconnection of means for the filling and/or emptying and/or means for thepressure default are arranged in the system in the closed circuit. Themeans for the pressure default are thereby preferably pressure tightconnected to the closed circuit and serve the purpose of generating astatic superposition pressure in the closed circuit. The means for thepressure default comprises preferably a pressure tight closed reservoir,which is pressure tight connected with the closed circuit. The pressuredefault takes place via applying a pressure on the reservoir level.Another possibility is the generation of a pressure through additionalcomponents, for example a suitable pump device.

The means for filling comprise an operating medium reservoir device anda means for the operating medium transport, for example pump devices.These serve also the purpose of loss compensation.

Under a further aspect of the invention the means for filling andemptying and the means for the pressure default are formed by a systemfor the purpose of the simplification of the overall system. Filling andemptying takes place preferably likewise by means of the reservoir,which is connected pressure tight to the closed system, and by applyingpressure on the reservoir level or by pump devices.

An improvement of the invention contains the provision and/or theallocation of standing back pressure tubes to the diverting area, whichis limited by a rotating housing component. Preferably a multiplicity ofstanding back pressure tubes is intended, which are arranged in acertain distance to each other in circumferential direction. The backpressure tubes function as a back pressure pump device when immersedinto the diverting area and are connected with the line connections,which are connected with the diverting area. These convert the kineticenergy into pressure energy and create automatically a cooling circuit,which is required for ensuring the continuous operation of thehydrodynamic clutch. In a further design of the solution according tothe invention means for the heat dissipation in the closed circuit areprovided. These can be cooling devices or heat exchangers.

The hydrodynamic clutch designed as a starting element according to theinvention is not limited to any specific application in drive trains.Application can take place in drive trains of stationary units or mobiledevices, preferably in a vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The solution according to the invention is in the following describedusing the following figures:

FIG. 1 illustrates a favorable design of a starting element in form of aturbo-clutch arranged according to the invention using a section of adrive train;

FIG. 2 illustrates the basic principle of the controlling of thevolumetric efficiency using a diagrammatic representation of ahydrodynamic clutch and the operating medium utility system assigned tosaid clutch.

DETAILED DESCRIPTION

FIG. 1 illustrates a favorable design of a starting element 1 in form ofa hydrodynamic clutch 2 arranged according to one form of the invention,in particular a turbo-clutch using a section of a drive train 3. Thehydrodynamic clutch 2, in particular a turbo-clutch, comprises at leastone primary wheel functioning as impeller 4 and a secondary wheelfunctioning as turbine wheel 5, which form with one another a toroidalworking chamber 6. The starting element 1 comprises further one driveunit 7, that can be coupled at least indirectly with a drive motor (notshown), and one output unit 8 that can be coupled at least indirectlywith the output unit at the drive system, i.e. indirectly via furthertransmission means or directly without inserting further transmissionmeans. The output unit 8 can generally be coupled with a mechanicalspeed and/or torque transformer during the application in gear boxes.The drive unit 7 and the output unit 8 are formed for example in eachcase by a shaft or a hollow shaft or a flange. The hydrodynamic clutch 2includes a housing 9, which is connected secured against torsion withthe impeller 4 and consists because of assembly reasons preferably of amultiplicity of individual housing components 25.1 -25.3. The housing 9is therefore likewise connected secured against torsion with the driveunit 7. In the represented case the housing 9 is therefore connectedwith a hub component 10, which is designed flange-like at its end 11facing the starting element, whereby the mounting, respectively theconnection, secured against torsion between the hub component 10 and thehousing 9 takes place in the area of a flange 12 of the hub component10. The drive of the hub component 10 takes place through a drive shaft13, which can be connected at least indirectly, i.e. either directly orover further power transmission components with a drive motor notrepresented here, and through a suitable shaft-hub connection 14 whichin the represented case is designed as key joint 15 between hubcomponent 10 and drive shaft 13. Other design variations for therealization of a connection secured against torsion are likewiseconceivable. The housing 9 encloses the turbine wheel 5 while forming afirst gap 16 in axial direction. The first gap 16 is thereby limited bya housing inner wall 17 of a housing component 25.1, by an outlet 18from the impeller in the range of the parting plane 19 between impeller4 and turbine wheel 5, by the outer circumference 20 in the range ofradially outer extension 21 of the turbine wheel 5, and by a furtherhousing component 25.2, which is connected secured against torsiondirectly with the impeller 4 or which forms a structural unit with theimpeller, in particular its inner surface 31. Means 22 are intended forsealing the gap 16 between the housing 9 and the turbine wheel 5. Thesemeans for sealing 22 comprise at least one non-contact sealing device23, which is designed preferably in form of a labyrinth seal. Thehousing 9 forms further a second gap 28 with the impeller 4 and afurther housing component 25.3, connected secured against torsion to theimpeller, as well as a second housing 51 with rotates with relativespeed in relation to the housing 9, is preferably however stationary,which is mounted via an arrangement of bearings 26 on a driven shaft 27which forms the output unit 8 of the starting element 1. This second gapis essentially formed by the outer surface 29 of the impeller 4 in theradially outer portion 30, by the housing component 25.2, which carriesthe housing inner wall 31, and by an inner surface 33 of the housingcomponent 25.3 of the housing 9, which at least partially encloses theimpeller 4 in axial direction. The stationary housing 51 can be designedas one-piece or as multiple pieces. It can also rotate—depending on theconnection to the output unit 8—with relative speed in relation to therotation of the housing 9. A seal between the housing component 25.3 anda housing component 51.1 of the stationary housing 51, into which lineconnections 41 for the realization of a closed operating medium circuit42 are integrated, is created by means 34 for sealing the gap 28 betweenthe housing 9 and the housing 51, in particular the housing components25.3 and 51.1. These means comprise at least a non-contact gasket 35,which is designed preferably in form of a labyrinth seal. The second gap28 is connected at the housing component 25.2 with the first gap 16 viasuitable transfer ports 36 in the housing wall 32. Means 37 for theremoval of operating medium appears in the second gap 28 during theoperation of the hydrodynamic clutch via the operating medium guide inthe toroidal working chamber 6, are assigned to the second gap 28, saidmeans being designed for example in the form of back pressure pumps 38.According to the desired amount of operating medium to be removed fromthe second gap 28 and the time period, which is available for theremoval, preferably in dependence on the possible passage area, which isdetermined by the dimensioning of the back pressure pumps 38, amultiplicity of back pressure pumps 38 is provided, which are preferablyarranged in symmetrical distances in circumferential direction in thegap 28, respectively submerged into the gap. The housing components 51.1and 51.2 and the third housing component 25.3 form a back pressure pumphousing 54, the housing component 25.3 for itself alone the impellershell 52. The housing components 51.1 and 51.2 can also be designed asan integral unit, i.e. only one housing component is provided, whichcombines the housing components 51.1 and 51.2 as represented in FIG. 1.The means for the removal 37, in particular the back pressure pumps 38,are connected with means 39 for directing of operating medium in aclosed circuit 42. The means 39 for directing the operating mediumcomprise therefore preferably line connections 41 in the form ofoperating medium channels 50, which are integrated into the housing wallfacing the impeller 4 respectively into the housing components 51.1 and51.2 of the housing 51. The rotating housing 25 and the housing 51,which is either stationary or rotating with relative speed to thehousing 25, form the total housing 55 for the clutch 2. The operatingmedium utility system 53 comprises an operating medium reservoir 40,which is connected with the closed circuit 42 via a knot location 56,for example by means of a line connection. The operating mediumreservoir 40 is preferably arranged in the area below the height of thetoroidal working chamber 6, in particular within the outer radialdimensions of the individual impellers 4 or 5 in assembled position. Inthis case a safety device via a siphon or other aids can be omitted.

The operating medium reservoir 40 is thereby pressure tight connectedwith the inlet 44 into the toroidal working chamber 6 via the junction56. The means for sealing 34 of the gap 28, in particular of the backpressure pump housing 54 and the impeller shell 52, as well as the means22 for sealing between turbine wheel 5 and the rotating housing 9 of thestarting unit 1 are spatially arranged in circumferential directionabove the meridian center and below the maximum profile diameter of thetwo impellers, i.e. the impeller 4 and the turbine wheel 5. Furthermoremeans 43 are provided for sealing between impeller 4 and turbine wheel5, whereby these means are arranged in radial direction inside theinternal diameter dE of the toroidal working chamber 6. The closedcircuit 42 is thus pressure tight in relation to its surrounding. Theconnection of the operating medium reservoir 40 to the closed circuit 42takes place likewise pressure tight.

The housing of the starting unit 9, the impeller 4, the turbine wheel 5,the closed circuit 42 as well as the pressure tight connection of theoperating medium reservoir 40 with the closed circuit 42 form means 45for the generation of a pressure balance between a closed rotatingcircuit 42 and a resting medium. The closed circuit 42 is providedbetween the outlet 18 from the toroidal working chamber 6 in the area ofthe parting plane 19 and the inlet 44 into the impeller 4. The operatingmedium arrives from the flow circuit in the toroidal working chamber 6via the outlets 18 in the area of the parting plane 19 of the impeller 4and the turbine wheel 5 and via the connection channels into the secondgap 28, from where the operating medium is directed via the means forthe removal 37, in particular the back pressure pumps 38, into theclosed circuit 42.

The inlet 44 is via the filling location 47 connected with the operatingmedium reservoir 40. In a particularly favorable design the fillinglocation 47 is furthermore designed as bladed channel 48. This meansthat direction components 49, which extend in the direction of the flowtoward the toroidal working chamber 6, are provided. The reduction ofthe operating medium stream via the outside impeller shell 52, formed bythe housing component 25.3, preferably takes place via a multiplicity ofstationary back pressure pumps 38, which are arranged to each other incircumferential direction preferably symmetrically. The circuit createdfor cooling purposes is thereby designed as closed circuit 42.

The working principle of the filling control by means of an outsidepressure onto a resting medium is described in diagrammatic simplifiedrepresentation in FIG. 2. This figure illustrates in diagrammaticsimplified representation a hydrodynamic clutch 2, the closed circuit 42assigned to the clutch, which is designed as a coolant circle, and theconnection between the turbo-clutch 2 and the operating medium reservoir40. The inlet into the working chamber 6 is shown to be arranged at theturbine wheel 5. The operating medium reservoir 40 is thereby forexample designed as tank or vessel, whereby it can also be formed by thehousing of the starting unit or of the gear box in which the startingelement 1 is arranged. The operating medium reservoir 40 is therebypreferably arranged below the internal diameter d_(E) of the toroidalworking chamber 6. It is thereby crucial that the operating medium levelis either below this dimension or it can be above, with the presence ofsuitable aids, for example in the form of siphons and/or valves. Theclosed coolant circuit 42 is designed between the toroidal workingchamber 6 respectively the outlet 18 from the toroidal working chamber 6and the filling location 47 of the toroidal working chamber 6. Means forthe heat dissipation of operating medium 57 are for example arranged insaid circuit. These means 57 comprise in the simplest case for example aheat exchanger or a cooling device. Directing the operating medium fromthe working chamber 6 into the working chamber 6 in the closed circuit42 serves thereby mainly the purpose of cooling the operating medium, inparticular the generation of a continuous cooling operating medium flow.The operating medium utility system comprises a pressure tight designedoperating medium reservoir 40, for example in form of an operatingmedium sump in a reservoir, a tank or a housing, which can be connectedvia at least one connection channel with the closed circuit 42 in thearea of the inlet 44. The operating medium reservoir 40 is therebypreferably arranged in such a manner that the arising operating mediumlevel is arranged underneath the toroidal working chamber 7. Aninfluence pressure P_(B) for the change of the volumetric efficiency FGis applied on the operating medium level, whereby said influencepressure during effect on the closed sump allows operating medium toenter the working circuit in the toroidal working chamber via connectionchannels, until the pressure within the area of the inlet 21 after theheat exchanger creates a pressure balance. Filling or emptying takesplace until a pressure balance between the operating medium level in theoperating medium reservoir and the rotary closed circuit arises.

Furthermore, as shown in FIG. 1, the profiles of the turbine wheel 5 andthe impeller 4 are offset in radial direction against each other by acertain value in such a manner that the outside profile diameter of theturbine wheel 5 exhibits a larger dimension in radial direction than theoutside profile diameter of the impeller 4 and the interior profilediameter of the turbine wheel 5 exhibits likewise a larger dimensionthan the internal diameter of the impeller profile.

A change of the ideal torus-symmetrical form can take place moreover viaa profile offset.

The back pressure pumps 38 supply with emptied turbo-clutch 2, when allcircuit parts are free of operating medium, a flow rate and an oilpressure for cooling or for actuation for other consumers, like forexample a wet-running mechanical clutch.

Further favorable designs include means for the improvement of thefilling of the working chamber, i.e. the pump characteristic, byproviding elements built into the filling area 48 connected with thefilling location 47. These elements built in can be designed as fillingblades 49, perforated plate packages or similarly designed areas.Furthermore it is conceivable to design the filling of the impeller 4through several blade cascades in arbitrary parts of the torus orthrough the blade itself, for example a stamped channel to the toruscenter.

Further improvements can have the blades of impeller 4 and turbine wheel5 designed with different blade angles. Additionally or as an individualsolution the blades of impeller 4 and turbine wheel 5 can be sharpeneddifferently, which entails into different dimensions across theextension in circumferential direction of the individual blade. Anotherpossibility consists of changing the entry angles and outlet anglesbetween impeller and turbine wheel or to provide a different number ofblades in the mounting of blades of impeller 4 and turbine wheel 5.

-   1 Starting element-   2 Turbo-clutch-   3 rive train-   4 Impeller-   5 Turbine wheel-   6 Toroidal working chamber-   7 Drive unit-   8 Output unit-   9 Housing-   10 Hub component-   11 End range facing the starting element-   12 Flange-   13 Drive shaft-   14 Shaft-hub connection-   15 Key joint-   16 Gap-   17 Housing inner wall-   18 Outlet-   19 Parting plane-   20 Outer circumference-   21 Radially outer extension-   22 Means for sealing-   23 non-contact sealing device-   25.1, 25.2,-   25.3 Housing component-   26 Arrangement of bearings-   27 Driven shaft-   28 Gap-   29 Outer surface-   30 radially outer range-   31 Inner surface-   32 Housing wall-   33 Inner surface-   34 Means for sealing the gap 28-   35 Non-contact gasket-   36 Transfer port-   37 Means for the removal of operating medium from the working    chamber-   38 Back pressure pump-   39 Means for directing the operating medium-   40 Operating medium reservoir-   41 Line connections-   42 Closed circuit-   43 Means for sealing between impeller and turbine wheel-   44 Inlet-   45 Means for the generation of a pressure balance between a closed    rotating circuit and a round medium-   47 Filling location-   48 Filling area-   49 Bladed direction components-   50 Operating medium channels-   51 Resting housing component-   52 Impeller shell-   53 Operating medium utility system-   54 Back pressure pump housing-   55 Total housing-   56 Knot location-   57 Means for heat dissipation-   d_(E) Inner diameter of the toroidal working chamber

1. A method for controlling the power-consumption of a starting element(1) in form of a hydrodynamic clutch (2), comprising an impeller (4) anda turbine wheel (5), which form with one another at least one toroidalworking chamber that can be filled with an operating medium (6), and islocated in a drive train (3) with at least one other drive motor thatcan be coupled to the hydrodynamic clutch (2), wherein the powerconsumption can be freely adjusted as a function of the volumetricefficiency of the hydrodynamic clutch (2), the method comprising:directing at least one portion of the operating medium in the workingchamber (6) during the operation of the hydrodynamic clutch (2) in aclosed rotating circuit (42) between at least one outlet (18) from thetoroidal working chamber (6) between the impeller (4) and turbine wheel(5) and at least one inlet (44) into the toroidal working chamber (6);influencing the supply of operating medium to the working chamber (6) orthe removal of operating medium from the working chamber (6) by thegeneration and introduction of a static superposition pressure into theclosed rotating circuit; supplying or removing the operating medium toor from the working chamber (6) via an operating medium reservoir (40)which is pressure tight connected to the inlet (44) in the toroidalworking chamber (6); wherein the supple of operating medium to theworking chamber (6) or the removal of operating medium from the workingchamber (6) takes place by applying a superposition or influencepressure to the operating medium level of the operating medium reservoir(40); and wherein when a value is present which characterizes the powerdesired to be received of the hydrodynamic clutch (2) at leastindirectly, creating a manipulated variable for the generation of aninfluence pressure on the operating medium resting in the operatingmedium reservoir (40), and triggering a servo unit that generates theinfluence pressure.
 2. The method according to claim 1, wherein a valueis present which characterizes the power desired to be desired to bereceived of the hydrodynamic clutch (2) at least indirectly, said valuecontrols the volumetric efficiency of the hydrodynamic clutch (2) inorder to change the power to be received.
 3. The method according toclaim 1, wherein the duration of the filling or emptying process ischaracterized by the length of time for the adjustment of a pressurebalance between the operating mediums present in the operating mediumreservoir (40) and the closed rotating circuit (42) of the operatingmedium.
 4. The method according to claim 1, and accomplishing thefilling and/or emptying of a complete filling in a time period of equalor smaller than 1s.
 5. The method according to claim 1, and controllingthe influence pressure in dependence of at least one of the followingparameters: speed of the impeller; value of the torque at the impeller;value of the torque at the turbine wheel, speed of the turbine wheel.6.The method according to claim 1, wherein the value of the componentcurrent of the operating medium present during the operation of thehydrodynamic clutch (2) in the working chamber (6), which is directed ina closed circuit (42) between at least one outlet (18) from the toroidalworking chamber (6) between the impeller (4) and turbine wheel (5) andat least one inlet (44) into the toroidal working chamber (6) iscontrolled independently of an effect on the power consumption dependenton the temperature in the working circuit in the toroidal workingchamber (6).
 7. A hydrodynamic clutch (2), comprising: an impeller (4)and a turbine wheel (5), which form with one another at least onetoroidal working chamber (6); means for directing the operating mediumin a closed circuit of at least one outlet (18) from the toroidalworking chamber (6) into at least one inlet (44) of the toroidal workingchamber (6); the closed circuit (42) being pressure tight; a junction(56) in the closed circuit (42); means for the optional connection ofmeans for the filling and/or emptying and/or means for the influence ofthe pressure of the operating medium which is directed in the closedcircuit (42) to the junction (56); a housing (9) which is connectedsecured against torsion with the impeller (4); the housing (9) enclosingthe turbine wheel (5) in axial direction while forming a first gap (16);the first gap (16) limited by the outer circumference of the turbinewheel (5), whereby a non-contact sealing device (23) is provided betweenthe housing (9) and turbine wheel (5); the housing (9) forming a secondgap (28) with a stationary housing component (51) into which means (37)submerge for the removal of operating medium from the impeller shell(52); a seal at the second gap (28) between the housing (9) and a roundhousing component (51); a seal between the impeller (4) and the turbinewheel (5) below the inside diameter (d_(E)) of the toroidal workingchamber (6).
 8. The hydrodynamic clutch (2) according to claim 7,comprising: an operating medium utility system (53) comprising anoperating medium reservoir (40) connected with the inlet (44) into thetoroidal working chamber (6); and a pressure tight connection betweenthe operating medium reservoir (40) and the inlet (44).
 9. Thehydrodynamic clutch according to claim 7, wherein the means (37) for theremoval of operating medium comprises at least one stationary backpressure pump device (38).
 10. The hydrodynamic clutch (2) according toclaim 7 wherein: the inlet (44) is connected with a filling area (48)via a filling location (47); the filling location (47) is designed as abladed channel (48) comprising direction components (49).
 11. Thehydrodynamic clutch (2) according to claim 10, wherein the directioncomponents (49) extend in the direction of the flow toward the toroidalworking chamber (6).
 12. The hydrodynamic clutch (2) according to claim7 wherein the profiles of the turbine wheel (5) and the impeller (4) areoffset by a certain value in the radial direction.
 13. The hydrodynamicclutch (2) according to claim 12, wherein the outside profile diameterof the turbine wheel (5) in the working chamber has in the radialoutward direction a larger dimension than the outside profile diameterof the impeller (4) in the working chamber.
 14. The hydrodynamic clutch(2) according to claim 7 wherein the inlet (44) into the toroidalworking chamber (6) is provided at the impeller (4).
 15. Thehydrodynamic clutch (2) according to claim 14, wherein the inlet intothe toroidal working chamber takes place via the blades.
 16. Thehydrodynamic clutch (2) according to claim 14, wherein the filling ofthe toroidal working chamber (6) takes place in the area of thestatically lowest pressure into the working chamber (6).
 17. Ahydrodynamic clutch (2), comprising: an impeller (4) and a turbine wheel(5), which form with one another at least one toroidal working chamber(6); means for directing the operating medium in a closed circuit of atleast one outlet (18) from the toroidal working chamber (6) into atleast one inlet of the toroidal working chamber (6); the closed circuit(42) being pressure tight; a junction (56) in the closed circuit (42);means for the optional connection of means for the filling and/oremptying and/or means for the influence of the pressure of the operatingmedium which is directed in the closed circuit (42) to the junction(56); the inlet into the toroidal working chamber (6) is arranged at theturbine wheel (5).